Doorbell



FIG. 1 is a front, side, and top perspective view of a doorbell embodying the new design;

FIG. 2 is a back, side, and bottom perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a back view thereof;

FIG. 5 is a first side view thereof, the second side view being a mirror image;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

In the drawings the dot-dash broken lines indicate the boundaries of the claim; the dash-dash broken lines depict environmental subject matter only. The broken lines form no part of the claim. 

CLAIM The ornamental design for a doorbell, as shown and described. 